Capgras Syndrome,
named for its discoverer, the French psychiatrist Jean Marie Joseph
Capgras. The person's primary delusion is that a close relative
or friend has been replaced by an impostor, an exact double, despite
recognition of familiarity in appearance and behavior. The patient
may also see himself as his own double. Also know as Delusional
misidentification, illusion of doubles, illusion of negative doubles,
misidentification syndrome, nonrecognition syndrome, phantom double
syndrome, subjective doubles syndrome.

Delusions
are false beliefs, sometimes with bizarre content, that are held
with strong conviction even in the presence of contrary evidence.
For persons suffering from Capgras Syndrome they typically believe
they exist in a world of impersonators. This feeling in a delusional
world of doubles can be so alarming that it drives the Capgras
sufferer to psychotic behavior. The syndrome typically has the
following characteristics:

The person is convinced that one or several persons known by the
sufferer have been replaced by a double, an identical looking
imposter.

The patient sees true and double persons.

It can may extend to animals and objects.

The person
is conscious of the abnormality of these perceptions. There is
no hallucination.

The double is usually a key figure for the person at the time
of onset of symptoms. If married, always the husband or wife accordingly.

Associated
Features:

Cerebral
lesions caused by head injury, which are often located in the
posterior area of the right hemisphere, where face recognition
is performed.

Schizophrenic
diseased conditions (paranoid-hallucinatory schizophrenia),
but also in affective and organic-psychic disturbances.

Affects
both sexes, but prevalent in women.

Differential
Diagnosis:

Some disorders have similar symptoms. The clinician, therefore,
in his diagnostic attempt, has to differentiate against the following
disorders which need to be ruled out to establish a precise diagnosis.

It has been
reported that the Capgras Syndrome and related substitution delusions,
that 35% have an organic etiology. Some researchers believe that
Capgras' syndrome can be blamed on a relatively simple failure
of normal recognition processes following brain damage from a
stroke, drug overdose, or some other cause. This disorder can
also follow after accidents that cause damage to the right side
of the brain. Therefore, controversies exist about the etiology
of Capgras Syndrome, some researchers explain it with organic
factors, others with psychodynamic factors, or a combination of
the two,

Treatment:

Individual therapy may be
best suited to treat the persons delusions. Persistence is needed
in establishing a therapeutic empathy without validating the person’s
delusional system or overtly confronting the system. Cognitive
techniques that include reality testing and reframing can be used.
Antipsychotics
and other drugs have been used with some success.

Cognitive-Behavioural
therapy, for treating delusions that is based on persistent gentle
discussions about evidence for the belief, might help overcome
the problem the person has with believing this substitution al
delusion against the available evidence.

A reasonable
pharmacological treatment approach for the person with delusional
disorder is a standard trial of an antipsychotic or SSRI at starting
doses commonly used to treat psychotic or mood disorders.